Stability is one of the most important factors which determines whether a compound or a mixture of compounds can be developed into a therapeutically useful pharmaceutical product.
Combinations of formoterol and budesonide are known in the art, see for example WO 93/11773 discloses such a combination that is now marketed as Symbicort® in a dry powder inhaler. There are a variety of other inhalers by which a respiratory product can be administered, such as pressurised metered dose inhalers (pMDI's). Formulations for pMDI's may require certain excipients as disclosed in WO 93/05765.
It has now been found that certain HFA formulations comprising formoterol and budesonide together with polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) exhibit excellent physical suspension stability.
Description
In accordance with the present invention, there is provided a pharmaceutical composition comprising formoterol, budesonide, HFA 227 (1,1,1,2,3,3,3-heptafluoropropane), PVP and PEG characterised in that the PVP is present from about 0.0005 to about 0.03% w/w and the PEG is present from about 0.05 to about 0.35% w/w.
Preferably the PVP is present in an amount of 0.001% w/w. Preferably the PVP is PVP K25 (PVP having a nominal K-value of 25).
Preferably the PEG is present in an amount of 0.3% w/w. Preferably the PEG is PEG 1000 (PEG having an average molecular weight of 1000 Daltons).
Preferably the concentrations of formoterol/budesonide are such that the formulation delivers formoterol/budesonide at 4.5/40 mcg, 4.5/80 mcg, 4.5/160 mcg or 4.5/320mcg per actuation.
The formoterol can be in the form of a mixture of enantiomers. Preferably the formoterol is in the form of a single enantiomer, preferably the R,R enantiomer. The formoterol can be in the form of the free base, salt or solvate, or a solvate of a salt, preferably the formoterol is in the form of its fumarate dihydrate salt. Other suitable physiologically salts that can be used include chloride, bromide, sulphate, phosphate, maleate, tartrate, citrate, benzoate, 4-methoxybenzoate, 2- or 4-hydroxybenzoate, 4-chlorobenzoate, p-toluenesulphonate, benzenesulphonate, ascorbate, acetate, succinate, lactate, glutarate, gluconate, tricaballate, hydroxynapaphthalenecarboxylate or oleate. Preferably the second active ingredient is budesonide, including epimers, esters, salts and solvates thereof More preferably the second active ingredient is budesonide or an epimer thereof, such as the 22R-epimer of budesonide.
The pharmaceutical compositions according to the invention can be used for the treatment or prophylaxis of a respiratory disorder, in particular the treatment or prophylaxis of asthma, rhinitis or COPD.
In a further aspect the invention provides a method of treating a respiratory disorder, in particular asthma, rhinitis or COPD, in a mammal, which comprises administering to a patient a pharmaceutical composition as herein defined.
The compositions of the invention can be inhaled from any suitable MDI device. Doses will be dependent on the severity of the disease and the type of patient, but are preferably 4.5/80 mcg or 4.5/160 mcg per actuation as defined above.
The concentration of PVP (0.001% w/w) used in this formulation has been found to give consistently stable formulations over the required dose range, incorporating a wide range of concentrations of the active components, and at a much lower concentration than indicated in the prior art.
The invention is illustrated by the following examples.